The performance of titanium composite coatings obtained through thermal spraying and microarc oxidation

Abstract

The development of composite coatings essential to improve the wear and corrosion resistances of the materials employed in numerous applications, such as automobile, chemical, medicine, construction, aerospace, and biomedical industries. In this study, we presented a double-layer coating technique, which consisted of a thermal-sprayed titanium (Ti) layer and a micro-arc oxidation (MAO) film on AISI 1020 steel. The effect of the composite coatings (Ti/MAO) on wear and corrosion resistance was investigated. To obtain a coating thickness from 250 µm to 450 µm, the prepared specimens were coated with Ti (99.9% pure) by arc spraying. Then, the Ti/MAO films were deposited on Ti coatings. The current density of MAO was fixed at 35 A/dm2, the voltages were 250, 300, 350, 400, and 450 V, and the duration of the MAO process was 10 min, Measurements of film thickness, microstructure, microhardness, X-ray diffractometry analysis, and scanning electron microscopic observation were performed for determining the characteristics of the composite coatings (Ti/MAO). Potentiodynamic polarization curves were used to compare the corrosion resistance of these composite coatings. A ball-on-disc wear test, using an oscillation friction wear tester, was carried out at room temperature according to the ASTM G99 standard to determine the wear resistance. Among all the specimens, Ti/MAO (400 V) had the greatest hardness, lowest friction coefficient, least weight loss, and longest sliding distance. The sliding distance of Ti/MAO (400 V) was about 1.7 times higher than those of Ti. The open-circuit potential of Ti/MAO (400 V) was about 1.7 times better than those of Ti. The corrosion currents of Ti/MAO (250 V) and Ti/MAO (400 V) were decreased by MAO about 95% and 92%, respectively. Although the corrosion current of Ti/MAO (400 V) was higher than that of Ti/MAO (250 V), Ti/MAO (400 V) had better effects in other tests. According to the results, Ti/MAO (400 V) presented the best performance among all the specimens and provided improved protection to both Ti and substrate.

Effect of Different Concentrations of Nano-Cubic Boron Nitride on the Preparation of TiO₂/Ti/Fe Composite Materials by Thermal Sprayed and Micro-Arc Oxidation

“…The sliding over distance of Thermal Ti and Ti/MAO-F were 10.3 m and 16.9 m respectively. 44) In this study, we further found that the addition of c-BN to the electrolyte increases the sliding over distance of all Ti/MAO to exceed 200 m.…”

“…On the wear track of Ti/MAO-F, large area abrasive and peeled holes could be observed and illustrated both abrasive wear and adhesive wear. 44) In Fig. 7(c) and (d), there were extensive nanoparticles on the worn surface but the plots, adhesive peeled holes, and micro-cracks could not be obviously observed.…”

“…In the previous study, it could be indicated that the corrosion resistance of thermal Ti had a great improvement by using MAO with particles free. 44) When c-BN was added from 0.3 g to 0.9 g, Table 1 EDS results of Ti/MAO-F and Ti/MAO-BN coatings.…”

“…The duty cycle (the ratio of the pulse time to the total time in a cycle), frequency, and operation time of the MAO process were designated to be 50%, 1,000 Hz, and 10 min. 44) The c-BN nanoparticles of size 50 to 60 nm were added to the electrolyte. The electrolyte temperature was set to 25°C by using a cooler system and the electrolyte was continuously stirred to keep the c-BN nanoparticles dispersed during the MAO treatment.…”

Electrospun nano-barium titanate/polycaprolactone composite coatings on titanium and Ti13Nb13Zr alloy

“…Additionally, it has been noted that the alloying elements (Al, Fe, and V) can, to some extent, trigger toxic and allergic reactions. [8][9][10] An innovative class of biomedical alloys, such as the Ti13Nb13Zr (TNZ) alloy, is used in medical implants. The TNZ alloy is made up of beta-alloys and has the advantage of high corrosion resistance due to its persistent passive layer, good adherence to the metallic substrate, and low rate of tissue disintegration in surrounding physiological fluids.…”